1 down. Horrid and sticky! 4 letters.
2 down. Tough plastic used instead of glass for windows. 7 letters.
3 down. Sailboat. 5 letters.
4 down. Hiker’s bag. 8 letters.
5 down. Funny use of language. 4 letters, 2 letters and 5 letters.
6 down. Toff. 6 letters and 5 letters.
10 down. Wisdom – moxie. 8 letters.
12 down. Ante meridiem hours. 7 letters.
15 down. Throb (anag.). 5 letters.
17 down. Error. 4 letters.