喜んでた

was happy, was pleased

→ 喜ぶ
喜ん be happy, be glad + Te-form (conjunctive) + Past tense
verb · past indicative Rare #37,546
was happy, was pleased Colloquial contraction of 喜んでいた.
JA: 彼はプレゼントをもらって、喜んでた。
EN: He was happy to receive the present.
Conjugation of 喜ぶ
Indicative past
喜んでた

みんなめちゃくちゃ喜んでた

Everyone was absolutely thrilled.

マジ喜んでた

They were really happy.

— バトル・ロワイアル (2000)

トム喜んでた

Was Tom happy?

みんなめっちゃ喜んでた

Everyone was really happy.