At-Taqleed linguistically is the placing of the matter in the neck with an encompassment of it. Then it is used to entrust or delegate the matter to the person, as if it has tied the matter to his neck.

It is like the poet said:

They were entrusted to your affair _ your accomplishment is due to Allah _ generous The arm, with the matter of war

And the meaning of At-Taqleed in accordance to the Istilaah (terminological convention):

At-Taqleed, according to its Shar’a meaning, is to act in accordance to the opinion of another without a Hujjah Mulzimah (A binding proof). That is like the ‘Aamiy taking the opinion of the Mujtahid or the Mujtahid taking the opinion of another Mujtahid