copperfasten

Meanings

1. To protect the timbers of (a ship) with plates of copper secured with copper nails or bolts.
2. To reinforce, strengthen; to make permanent, embed.

Etymology

From copper + fasten. From copper sheathing of ship hulls (to protect from damage by marine organisms. Originally copper sheathing but non-copper bolts were used, leading to corrosion. Later copper bolts (fasteners) were also used, eliminating corrosion issues. Literal sense from 18th century, metaphorical sense attested 1948.