Proceed left with one fancy hat for David’s target (7)
I believe the answer is:
goliath
'david's target' is the definition.
I can't tell whether this defines the answer.
'proceed left with one fancy hat' is the wordplay.
'proceed' becomes 'go' (synonyms).
'left with' becomes 'l' (common abbreviation. I am not sure about the 'with' bit.).
'one' becomes 'I' (Roman numeral).
'fancy' indicates anagramming the letters.
'hat' anagrammed gives 'ath'.
'go'+'l'+'i'+'ath'='GOLIATH'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for goliath that I've seen before include "Giant Philistine laid low by David" , "David laid him low with slingshot" , "Giant Philistine felled by David" , "an unusually tall person" , "Giant Philistine killed by David" .)