-some /s ə m/ AmE suffix
[ Sense 1: Language: Old English ; Origin: -sum ]
[ Sense 2: Origin: some ]
1 . [in adjectives] tending to behave in a particular way, or having a particular quality:
a troublesome boy (=who causes trouble)
a bothersome back injury (=that bothers you)
2 . [in nouns] a group of a particular number, for example in a game:
a golf foursome (=four people playing golf together)