Transliteration: rtsal
<noun> Defined as the ནུས་པ་ "potential" or the particular type of force which is contained within something and which could be expressed. For example, an athlete trains the རྩལ་ physical ability present in their body so that it can be expressed to a high degree. This kind of training is called རྩལ་སྦྱོང་བ་ training the ability for expression that is present.The term is used in a wide variety of contexts. There is no one word in English that captures the meaning fully and various words must be used in context.
I. E.g., in reference to the manual skill or dexterity of anyone practising a manual craft or sport. E.g., the skill of a potter, the skill of an archer. The terms that have been used on occasion to translate it "skill", "dexterity", "adroitness", are what come of training the liveliness rather than being the liveliness itself.
II. "Expressivity", "liveliness". It is heavily used as path terminology in the highest tantras where it is a key term in both ཕྱག་རྒྱ་ཆེན་པོ་ Mahāmudrā and རྫོགས་པ་ཆེན་པོ་ Great Completion systems. In these systems, it is used to refer the capability of the སེམས་ཀྱི་ངོ་བོ་ essence of mind itself to come out into expression. Although this is commonly being translated as "expression" these days, that is not the meaning of the term; "expressivity" as the ability for expression would be correct. Alternatively, "liveliness" is very close to the intended meaning. Formality aside, the real meaning of the term in this case is the "spunk" of the essence of mind. The get-up-and-go possibility of the essence of mind itself. "Spunk" really matches the intended meaning but some people have problems with this because "spunk" has sexual overtones such as the semen. Funnily enough, this is the meaning intended here; it is the juice of the essence of mind that actually is the means by which the essence of mind comes out into expression. This is not counter to the Tibetan definitions, either; it is usually glossed as སེམས་ཀྱི་ངོ་བོ་ནུས་པ་ the "potential of the essence of mind" and potential is one of many synonyms for ཁུ་བ་ the "juicy spunk" of a man.
The term is defined as the ནུས་པ་ potential for expression which is contained within something, however the term is very dynamic and has the sense of the spunk as it actually does its business, like the semen squirting out and making patterns everywhere. You might think this is strange wording for a dictionary but this term has a very deep meaning in the context being explained; it contains a strong sense of the power, the strength of the essence as an actual dynamic force that shows itself dynamically and vividly as the realm of reality.
Another example given when explaining the meaning is that of a horse. Firstly, : a young horse has the potential for racing like a thoroughbred, i.e., it has རྩལ་ and the thoroughbred when racing, with its muscles rippling is displaying its རྩལ་. For these reasons the terms "expressivity" and "liveliness" seem suitable. If the term were used only according to its strict definition of "a potential" then the term "expressive power" might be acceptable. And equally, if the term were used solely as the fact of the expression then the word "expression" which has been coming into vogue would also be useful. Since both senses are in use, "expressivity" or "liveliness" seem better. Also, there is the important point that must be taken into account by translators that term is not dry or philosophical in tone. When the term རྩལ་ is used in Tibetan, the feeling of energy and dynamism comes with it. Therefore, terms like "expressive power" whilst perhaps getting at the defined meaning fall a long way short because of their "dry" feeling. In part for this reason, this translator prefers the word "liveliness".
It should be said that the word "spunk" in English is very close to the meaning of རྩལ་ in the sense of potential and energetic display both. In many ways this translator thinks it a most suitable term, including the word, "spunkiness" which would be needed. There is the problem though that some Westerners might think only of sexual connotations, most unfortunately.
This term is a key term in both ཕྱག་རྒྱ་ཆེན་པོ་ Mahāmudrā and རྫོགས་པ་ཆེན་པོ་ Great Completion systems. The term means the potential that the innate mind contains to express itself. And as mentioned above, the common example given is that of a baby horse has the innate ability that will later come out as its liveliness of galloping and prancing as a steed. Also as mentioned above, the word is used in situations where the innate mind is actually expressing itself; it's "expressivity is on display" or there is "the play of the liveliness of the innate mind happening". This is a key point in these traditions of meditation because the beginning practitioner spends a long time dissolving the sense of themselves and in doing so tends to think of enlightenment as a rather static, empty situation. The teaching on liveliness shows the student that the innate mind can be dynamic without a sense of self being present. In particular, the student is guided into having the innate mind's expressivity manifest itself as a dynamic display which is for the benefit of others. I.e., they are introduced to the རྩལ་ of their own, innate minds and shown how it could not be left as mere potential but could be brought to life and allowed to display. In this usage, the term རྩལ་ is similar to the meaning གདངས་ of the innate mind. In these systems, when the རྩལ་ has been trained so that it is now manifest, it is called རྒྱན་ "ornamentation".