plural of lock
"She ran her fingers through her long, curly locks in the morning light."
a head of hair, tresses
Third-person singular simple present indicative form of lock
"The heavy iron locks on the vault door are currently engaged and cannot be opened without a key."
In plain English: To lock something means to secure it so that no one can open it without a key.
"She locks the front door before leaving for work."
A surname.
"The famous scientist Mr. Locks presented his findings at the conference yesterday."
The word locks is simply a variant spelling of lock. It entered English with no change in meaning or origin from its original form.