When something obtrudes or when you obtrude it, it becomes noticeable in an undesirable way.
例句
A 40 watt bulb would be quite sufficient and would not obtrude...40瓦的燈泡完全夠亮了，并且不會晃眼。Gertrude now clearly felt that she had obtruded her sorrow...格特魯德此時明顯察覺自己的悲傷情緒已影響到他人。