All done except for 21 across. I think the definition is GRASS and I have found two words which would fit the letters I have (TE_F), but cannot parse it. Have I gone wrong somewhere?
The best I could come up with for TERF is -
'wanting tips for each' = 'tips' (as in turning over) + 'for each' (as in the sense of 'being restricted to two') 'fret' can mean both 'offence' ('irritation' in Chambers) and 'harass'.
It's a long shot!