to push in stealthily
• (v. t.) To place under; to insert.
Sub·trude' transitive verb [ imperfect & past participle Subtruded ; present participle & verbal noun Subtruding .] [ Prefix sub- + Latin trudere to thrust.] To place under; to insert. [ R.] 
subtrude, subtruding, subtruded 1. To push in stealthily or secretly. 2. To place under or to insert under something.