plural of northern fur-seal

plural of Ladoga ringed seal

plural of Caribbean monk seal

plural of Guadalupe fur seal

plural of Galápagos fur seal

plural of radial shaft seal

plural of sealed system

Any device with inner workings obscured.

Wax formerly melted onto a letter to seal it; the picture of the sender's seal was often pressed into the wax as evidence that the letter had not been opened.

An arctic seal, Cystophora cristata, notable for the fleshy bulge on its forehead and nose.