The correct spelling of the phrase "hitched on" is /hɪtʃt ɒn/. The word "hitched" refers to joining or connecting something to another, usually with the use of a hook or a knot. Meanwhile, the word "on" is a preposition used to indicate the location or position of something. The spelling of the word "hitched" is derived from the verb "hitch," which means to attach. When used together with the preposition "on," these two words form an idiomatic expression that refers to attaching something to another object or surface.