Sailor almost showing courage (5)
I believe the answer is:
heart
'courage' is the definition.
(I know that heart is a type of courage)
'sailor almost' is the wordplay.
'sailor' becomes 'hearty' (I've seen this before).
'almost' means to remove the last letter (most of the word but not all of it).
'hearty' with its last letter taken away is 'HEART'.
'showing' is the link.
(Other definitions for heart that I've seen before include "Blood-pumping organ" , "Feeling" , "one needs to beat" , "Earth (anag) -- compassion" , "Player for Scottish team" .)