Definitions

1. noun

a deposit of lime, especially a hardened deposit formed in a pipe or vessel

“The calx in the pipe had to be removed before the water flowed freely.”

2. noun

a deposit of lime, especially one formed by the incrustation of water containing lime

“The calx on the walls of the ancient building was a result of centuries of weathering.”

3. verb

to form a calx on something

“The pipe was calxed with a hard, white deposit.”