toe: (noun) body part; digit of the human foot; part of footwear that covers front of foot; (verb) push, touch or kick something with front of foot
Part of the expression “to toe the line”.
tow: (verb) pull, drag or haul something (often a vehicle) behind you; (noun) the act of towing; rope or line used to tow
NOT part of the expression “to toe the line”.