Low spirits? Start drinking ancient spirits (8)
I believe the answer is:
doldrums
'low spirits?' is the definition.
(I've seen this before)
'start drinking ancient spirits' is the wordplay.
'start' suggests taking the first letters.
'ancient' becomes 'old' ('old' can be similar in meaning to 'ancient').
'spirits' becomes 'rums' (I've seen this in other clues).
The initial letter of 'drinking' is 'd'.
'd'+'old'+'rums'='DOLDRUMS'
(Other definitions for doldrums that I've seen before include "Belt of calm where winds from north and south come together" , "Low spirits -- calm part of the ocean" , "Belt of calm where winds from the northern and southern hemispheres come together" , "Depressed state - area around the Equator" , "blues" .)