the word "tunnel-like" is a modern english compound adjective formed by combining the noun "tunnel" with the suffix "-like". the noun "tunnel" has a fascinating journey, originating from the old french word for a cask (tonne), which evolved to mean a tubular net (tonnelle) and was later applied to underground passages due to their similar cylindrical shape. the suffix "-like" descends from the old english word for body or form (līc), which became a productive way to denote resemblance. therefore, the literal construction "having the form of a tunnel" perfectly captures the modern meaning of something long, narrow, and enclosed, directly linking the physical object to its descriptive quality.

Structure: tunnel (noun) + like (adjective suffix) - tunnel: from middle english tonel, tonnel (a tubular net or funnel), from old french tonnelle (net), diminutive of tonne (cask, tun). in this compound, it functions as the base noun specifying the object of resemblance. - like: from old english līc (body, form, likeness), from proto-germanic līką. in this compound, it functions as a suffix meaning "having the form or characteristics of".