Bedeutung von “alternate” im Essential American English Dictionary

alternate

verb us /ˈɔl·tərˌneɪt/ present participle alternating, past tense and past participle alternated

If two things alternate, one thing happens, then the other thing happens, then the first thing happens again:

Alternate layers of fruit and yogurt in a tall glass.
She easily alternates between Spanish and English.

(Definition von “alternate verb” aus dem Webster's Essential Mini Dictionary © Cambridge University Press)