The subject of today's crossword was KANGAROO WORDS, or self-contained synonyms.
Isn't this interesting !

PRECIPITATION.....R-A-I-N
CLOSEMOUTHED....M-U-T-E
CONTAMINATE...T-A-I-N-T
UNSIGHTLY.....U-G-L-Y
RAMBUNCTIOUS...R-A-U-C-O-U-S
PREMATURELY....E-A-R-L-Y
FABRICATION....F-I-C-T-I-O-N
HONORABLE....N-O-B-L-E
MASCULINE....M-A-L-E
DESTRUCTION...R-U-I-N