Volunteers, at the outset, to try (5)
I believe the answer is:
taste
'try' is the definition.
(synonyms)
'volunteers at the outset' is the wordplay.
I cannot really understand how this works, but
'volunteers' could be 'ta' (abbreviation for Territorial Army) and 'ta' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
The remaining letters 'se' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for taste that I've seen before include "to eat in small amounts" , "Selectivity" , "Brief sample; discernment" , "Delicacy" , "Show sense" .)