Like soldiers initially welcoming times in Gulf (5)
I believe the answer is:
abyss
'gulf' is the definition.
(I've seen this in another clue)
'like soldiers initially welcoming times' is the wordplay.
'like' becomes 'as'.
'initially' indicates taking the first letters.
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'times' becomes 'by' (both can mean 'multiplied by').
The initial letter of 'soldiers' is 's'.
'as'+'s'='ass'
'ass' enclosing 'by' is 'ABYSS'.
'in' acts as a link.
(Other definitions for abyss that I've seen before include "Very deep gorge" , "deep depression" , "Fathomless pit" , "Primal chaos" , "Deep pit" .)