toàn

Etymology
.

The expected reflex of the Middle Chinese form would be (cf.  >,  > ,  > );  is the singular case where its usage persists in all dialects. The now dominant form toàn is a Northern innovation, displaced the earlier common form tuyền. Aside from the aforementioned exception, the form tuyền was still used to some extent in the Southern dialects until the 20th century (both as a stand-alone morpheme and in compounds such as ).

toàn (tŏàn) as a reading of is attested once, in  in Dictionarium Annamiticum Lusitanum et Latinum (1651), a dictionary chiefly based on the Northern dialects, while  is attested thrice (once as header, twice in, an indirect predecessor of modern ). In Dictionarium Anamitico-Latinum (1838), a dictionary based chiefly on the Southern dialects, the form toàn has no entry, while tuyền is abundantly attested.

The Dictionarium Annamiticum Lusitanum et Latinum (1651) has this about the similar sounding word :

Prefix

 * 1) pan-; all; entire; whole