the manner in which or the efficiency with which something reacts or fulfills its intended purpose.
8.
Linguistics. the actual use of language in real situations, which may or may not fully reflect a speaker's competence, being subject to such nonlinguistic factors as inattention, distraction, memory lapses, fatigue, or emotional state.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a chattering or flighty, light-headed person.
a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.
an extraordinary or unusual thing, person, or event; an exceptional example or instance.