Upon this discussion with YellowSky, a follow-up question arose:
There are some adjectives ending in -тный which could be grammatically possibly originated from both a noun and a verb with -т- not being a part of the verb's infinitive stem.
Of those adjectives, are there such which for semantic reasons can definitely be said to have originated from the noun and not from the verb?
Here are some examples:
Рукопожатный can (theoretically) be derived both from пожать руку and рукопожатие, since they define the same concept. Same with кровопролитный, старожитный etc.
Занятный ("amusing, interesting") cannot be derived from занятие but only from занимать ("take one's attention, curiosity, interest"), since занятие does not have this metaphorical meaning. Same with понятный etc.
Приметный ("related to omens, superstitions", as in народно-приметный календарь) is definitely originated from примета and not приметить, however, -т- here is a part of the verb's stem.
Рвотный ("emetic") could only be originated from рвота and not рвать, because рвать lacks -о-. Same for блевотный, тошнотный etc.