tamp

Concise Oxford English Dictionary © 2008 Oxford University Press:
tamp/tamp/

▶verb

• 1 pack (a blast hole) full of clay or sand to concentrate the force of the explosion.

• 2 firmly ram or pack (a substance) down or into something.

– origin C19: prob. a back-form. from tampin (interpreted as ‘tamping’), var. of tampion.