verb
submerse
sub-MURS/sʌbmˈɝs/
To put or go completely under water or another liquid.
She submerses the jars in water to loosen their labels.

Etymology
“Under” and “plunge” give the same underwater image as in submerge. Modern use may have been formed from submersion, the noun for the act or state of being submerged.
More examples
- He submersed the sponge in warm, soapy water.
- Keep the cloth submersed in the solution for five minutes.
- The submarine submerses until it disappears from view.
Forms
submerse · submerses · submersed · submersing
submersion noun — The state of being completely under liquid.