1 across. Hopeless. 6 letters.
4 across. Nervous – as a flea or frog? 5 letters.
7 across. Solar system member? 6 letters.
8 across. Thwack. 6 letters.
9 across. Lowest (of tides). 4 letters.
10 across. Plot together. 8 letters.
12 across. HGV operator? 5 letters and 6 letters.
17 across. Huff. 8 letters.
19 across. Grey matter – brown or white sliced food? 4 letters.
20 across. Nocturnal antipodean marsupial. 6 letters.
21 across. Venetian area and bridge. 6 letters.
22 across. Siren (anag). 5 letters.
23 across. Study of language structure. 6 letters.