As a noun sleet is
(chiefly|uk|ireland) a mixture of rain and snow.
As a verb sleet is
(impersonal|of the weather) to be in a state in which sleet is falling.
Not English Acidrain has no English definition. It may be misspelled.
(chiefly, UK, Ireland) A mixture of rain and snow.
Rain which freezes before reaching the ground.
(firearms) Part of a mortar extending from the chamber to the trunnions.
* ice pellets
* freezing rain
(impersonal, of the weather) To be in a state in which sleet is falling.
- I won't bother going out until it's stopped sleeting .
AMS Glossary of Meteorology