ненавременен означава в английски

inopportune▼(at an inconvenient or inappropriate time)
adjective
[UK: ˌɪn.ˈɒ.pə.tjuːn] [US: ˌɪ.ˌnɑː.pər.ˈtuːn]

untimely▼(taking place at an inopportune time)
adjective
[UK: ʌn.ˈtaɪm.li] [US: ʌn.ˈtaɪm.li]