Crossword Genius

A letter gets mailed out? That's wise (7)

Ross

I believe the answer is:

sapient

'wise' is the definition.
('sapient' can be similar in meaning to 'wise')

'a letter gets mailed out?' is the wordplay.
'letter' becomes 'pi' (pi is a kind of letter**).
'gets' means one lot of letters go next to another.
'mailed' becomes 'sent' ('send' can be a synonym of 'mail').
'out?' means one lot of letters goes inside another.
'a'+'pi'='api'
'api' going inside 'sent' is 'SAPIENT'.

'that's' is the link.

(Other definitions for sapient that I've seen before include "Acutely insightful and wise" , "very keen" , "Discerning" , "Literary word for wise" , "Canny" .)

I've seen this clue in The Independent.
Want a hint initially instead of a full solution? Install my app