Sentence:  Although there is no question but that the process of washing fabrics involves a number of phenomena which are related together in an extremely complicated way and that these phenomena and their interrelations are not <WSD>well</WSD> understood at the present , this section attempts to present briefly an up-to-date picture of the physical chemistry of washing either fabrics or hard surfaces . 
Meaning of the word marked with <WSD> tags:  (often used as a combining form) in a good or proper or satisfactory manner or to a high standard (`good' is a nonstandard dialectal variant for `well')