Left the day before with latitude to get even (5)
I believe the answer is:
level
'even' is the definition.
(synonyms)
'left the day before with latitude' is the wordplay.
'left' becomes 'l' (common abbreviation).
'the day before' becomes 'eve' (eve is the night before something).
'with' means one lot of letters go next to another.
'latitude' becomes 'L' (abbreviation for latitude).
'l'+'eve'+'l'='LEVEL'
'to get' acts as a link.
(Other definitions for level that I've seen before include "Absolutely horizontal" , "Having a flat, horizontal surface" , "Horizontal line" , "Device ot establish a flat surface" , "Equal; flat" .)