en_tn_condensed/isa/36/02.md

the chief commander

Some versions of the Bible translate this as "the Rabshakeh." This is the Assyrian word for one of the highest ranking military leaders in Assyria.

Lachish

This is a city southwest of Jerusalem.

conduit

man-made ditch or tunnel through which water flows.

the launderers' field

Possible meanings are 1) this is the proper name by which the people called the field or 2) this is the common noun that the people used to talk about the field, "the launderers' field" or "the field where men wash wool" or "the field where women wash clothes."