wit

wit /ˈwɪt/ noun
plural wits
wit
/ˈwɪt/
noun
plural wits
Britannica Dictionary definition of WIT
1 
[noncount] : an ability to say or write things that are clever and usually funny
2 
[count] : a person who is known for making clever and funny remarks — see also half-wit, nitwit
3 
a  wits [plural] : the ability to think or reason
— see also battle of wits at 1battle
b  the wit : the ability to make good decisions

at (your) wit's end

(chiefly US) or at (your) wits' end
: not able to continue thinking or trying to solve a problem : upset and unable to think of what needs to be done

out of your wits

informal
— used for emphasis with verbs like scare and frighten

to wit

formal
— used before stating the specific thing or example being discussed