A quiet, boring time gets you yawning (5)
I believe the answer is:
agape
'yawning' is the definition.
(synonyms)
'a quiet boring time' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'boring' is an insertion indicator (some letters must 'bore' a hole into other letters).
'time' becomes 'age' (an age is a period of time).
'a'+'p'='ap'
'ap' inserted into 'age' is 'AGAPE'.
'gets you' is the link.
(Other definitions for agape that I've seen before include "the love of God!" , "(Of mouth) wide open" , "love feast" , "Astonished" , "love a Christian shows" .)