Male in one card game showing restlessness (10)
I believe the answer is:
impatience
'restlessness' is the definition.
(impatience is a kind of restlessness)
'male in one card game' is the wordplay.
'male' becomes 'm' (common abbreviation).
'in' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'card game' becomes 'patience' (patience is a kind of card game**).
'i'+'patience'='ipatience'
'm' placed into 'ipatience' is 'IMPATIENCE'.
'showing' acts as a link.
(Other definitions for impatience that I've seen before include "Irritation at delay" , "which poor waiter reveals" , "Lack of tolerance" , "Inability to endure or wait" , "Unreasonable haste" .)