Seek is an English verb.
Seek is an irregular verb - it has the third person form seeks, the ing form seeking, but an irregular preterite and past participle 'sought'.
Seek is a transitive verb; one has seek something. Contrast look which is an intransitive verb with broadly similar meaning, so we seek something but look for something.
Sought can be a homophone with sort in non-rhotic accents. If th is substituted for /s/ then sought can be a homophone with thought (from think).
Note the phrasal verb "seek out" which just means seek.
Note the adjective "sought after"