Fortify

Part of speech: verb (v.)

1. To add strength to; to strengthen; to confirm; to furnish with power to resist attack. Timidity was fortified by pride. Gibbon. Pride came to the aid of fancy, and both combined to fortify his resolution. Sir W. Scott.

2. To strengthen and secure by forts or batteries, or by surrounding with a wall or ditch or other military works; to render defensible against an attack by hostile forces.

Part of speech: verb (v.)

To raise defensive works. Milton.