Discourteous old worker squashing females (7)
I believe the answer is:
offhand
'discourteous' is the definition.
(I've seen this before)
'old worker squashing females' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'worker' becomes 'hand' (hand is a kind of worker**).
'squashing' indicates putting letters inside (I've seen this in other clues).
'females' becomes 'ff' (I've seen this in other clues).
'o'+'hand'='ohand'
'ohand' going around 'ff' is 'OFFHAND'.
(Other definitions for offhand that I've seen before include "Without consideration" , "Casually thoughtless or inconsiderate" , "Cool in manner" , "Ungraciously cool" , "Casually rude" .)