One teases, initially showing chest (7)
I believe the answer is:
scoffer
'one teases initially' is the definition.
I can't tell whether this defines the answer.
'showing chest' is the wordplay.
'showing' becomes 's' (this might be a standard abbreviation I've not previously seen).
'chest' becomes 'coffer' (coffer is a kind of chest).
's'+'coffer'='SCOFFER'
Can you help me to learn more?
(Other definitions for scoffer that I've seen before include "One who scorns" , "Scornfully derisive person" , "One to ridicule" , "One who pokes fun" , "One derides" .)