verb/ensimisˈmaɾ/
to become lost in thought; to become engrossed, to lose oneself; to become conceited, "full of oneself"
“"[…] Así es él cuando algo le preocupa, se ensimisma, se sustrae de la realidad, pierde hasta la noción del tiempo y el espacio. Ni siquiera me miró…"” — " […] That's what he's like when something worries him, he gets lost in thought, he removes himself from reality, he even loses track of time and space. He didn't even look at me…"
Synonyms: abstraerse, envanecerse
From en (“in”) + sí mismo (“oneself”) + -ar (verbal suffix).