Fetching details from the dictionary...
somehow (or other); for some reason; without knowing why
something (or other); some ... or other
今日は何かしら不安な感じがする。
I somehow feel uneasy today.
この事件には何かしら彼に関係する。
This incident is somehow related to him.
天気予報を見ると何かしら明日の旅行が心配になる。
When I check the weather forecast, I somehow get worried about tomorrow's trip.