A lot of attempts to keep time may be unconvincing (5)
I believe the answer is:
trite
'unconvincing' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?
'a lot of attempts to keep time' is the wordplay.
'a lot of' means to remove the last letter (most of the word but not all of it).
'attempts' becomes 'tries' ('try' can be a synonym of 'attempt').
'to keep' means one lot of letters goes inside another.
'time' becomes 't' (abbreviation).
'tries' with its final letter taken away is 'trie'.
'trie' placed around 't' is 'TRITE'.
'may be' acts as a link.
Can you help me to learn more?
(Other definitions for trite that I've seen before include "Commonplace, hackneyed" , "all vigour is gone" , "Stock" , "used till novelty's worn off" , "Dull, unoriginal" .)