chum
US
UK chum n: informal, dated (friend, buddy) (非正式用语，过时用语)
SC 好友，朋友，伙伴 hǎo yǒu，péng yǒu，huǒ bàn
TC 朋友，夥伴 / 伙伴
TC 朋友，夥伴 / 伙伴
We've been chums since primary school.
chum n: mainly US (fishing: bait)
SC 鱼饵 yú ěr
SC 钓饵 yú ěr，diào ěr
SC 诱饵 yú ěr，yòu ěr
We threw some chum in the water and fish came immediately.
bosom buddy, bosom chum, bosom pal n: US, informal (close friend)
SC 密友 mì yǒu
The girls were bosom buddies until they both got a crush on the same boy.