Capricious (7 letter answer)
The answer ERRATIC is seen occasionally, appearing about once every 600 puzzles.
Hit or miss
All over the place
ERRATIC as an adjective:
1. (erratic, planetary, wandering) = having no fixed course; "an erratic comet"; "his life followed a wandering course"; "a planetary vagabond"
2. (erratic, fickle, mercurial, quicksilver) = liable to sudden unpredictable change; "erratic behavior"; "fickle weather"; "mercurial twists of temperament"; "a quicksilver character, cool and willful at one moment, utterly fragile the next"
3. (erratic, temperamental) = likely to perform unpredictably; "erratic winds are the bane of a sailor"; "a temperamental motor; sometimes it would start and sometimes it wouldn't"; "that beautiful but temperamental instrument the flute"- Osbert Lancaster