lockfast adjective. 
['lɒkfɑ:st] LME.[Sense 1 from LOCK noun2 + FAST adjective; sense 2 from LOCK verb1 + FAST adverb.]1.  Fastened or secured by a lock. Chiefly 
Scot. LME.2.  Adapted for locking something securely. 
L19.  [TahlilGaran] English Dictionary ▲