To be locked together; mutually engage, clasp, or cling: embrace: as, the interlocking boughs of a wood.To lock or clasp together; lock or hitch one in another: as, cattle sometimes interlock their horns.In geography, to be involved together: specifically applied to the headwaters of two different drainage systems which dovetail together yet flow in opposite courses.To cross-lock or lock in combination; lock so that unlocking can be effected only under certain conditions, or after certain other motions have previously been made.