Specialists in Chinese historical phonology have claimed that some Vietnamese words with final /-j/ come from Old Chinese words with final *-r. This is reasonable to speculate as Proto-Austroasiatic finals *-r and *-l became final /-j/ in Vietnamese, parallel to the case in Sinitic. However, these Vietnamese words offer little evidence for OC *-r. Vietnamese did borrow a number of Late Old Chinese or Early Middle Chinese words reconstructed with final *-r after *-r merged with *-n in Eastern Han or later, and thus these words also have /-n/ in Vietnamese. Several other Vietnamese words with final /-j/ which are possibly from Old Chinese words having *-r were borrowed earlier in the BCE period, likely before large migrations of Sinitic speakers arrived. Those words include verbs and an adjective, words less likely than nouns to be borrowed without large bilingual communities. The small number of words and general uncertainty suggests some Vietnamese words with /-j/ purportedly from Old Chinese words with *-r may be chance similarities. Few are probable Chinese loanwords from that period.
Ferlus (1997) uses the term “Viet-Muong” which is generally considered to be a sub-branch within Vietic (e.g. Hayes 1992; Nguyễn 1995; Diffloth 1992; Sidwell 2009).
Ferlus (1997) used ‘y’ to indicate IPA /j/.
Haudricourt (1954) and Nguyễn (1995) both posited Vietnamese words they considered to come from OC words with final *-r. Nguyễn (1995: 209) noted evidence among rhymes in the Shijing 詩經 and the possibility of these words having final *-r or *-l. None of the items in Table 9 have been reconstructed with final *-r by Baxter & Sagart (2014) and thus are not considered further in this study. All have the final /-j/ off-glide lacking in the MC era SV forms which suggests that they were borrowed in the pre-Tang era of EMC or the late OC era of the Eastern Han or Western Jin. Sagart (1999: 67) notes another source of Vietnamese ‘lazy’ namely 惰 ‘lazy’ OC *lˤojʔ though in that case the level tone in Vietnamese is unexpected for an OC word with final glottal stop.
In Baxter & Sagart’s (2014) notation brackets indicate that different data sources suggest different possibilities for reconstructions which is the case for three of the eight items.