> (As it happens, "performant" is at the stage where it is starting to pass those thresholds, and is now in the OED [2])
Strictly speaking, I don't believe your [2] is the OED. It's "Oxford Living Dictionaries", which I assume tries to be more current/dynamic, but might be regarded as less authoritative.
Interestingly, the word "performant" is in the OED itself, with the earliest citation being from 1809 -- but it is listed only as a noun, meaning "A person who performs a duty, ceremony, etc., a performer", not the adjectival usage under discussion here.
Strictly speaking, I don't believe your [2] is the OED. It's "Oxford Living Dictionaries", which I assume tries to be more current/dynamic, but might be regarded as less authoritative.
Interestingly, the word "performant" is in the OED itself, with the earliest citation being from 1809 -- but it is listed only as a noun, meaning "A person who performs a duty, ceremony, etc., a performer", not the adjectival usage under discussion here.
http://www.oed.com/view/Entry/262085?redirectedFrom=performa... (requires login)