plat (v.) Look up plat at Dictionary.com
"to interweave," late 14c., variant of plait (v.). Related: Platted; platting.
plat (n.) Look up plat at Dictionary.com
"piece of ground," 1510s, a variant of plot (n.) assimilated to Middle English plat (adj.) "flat," which is from Old French plat "flat, stretched out" (see plateau (n.)). See OED for full explanation.