Out of curiosity, I looked for words with sara อุ or อู combined with ฐ/ญ/ฎ/ฏ. I found only one such word in this site's dictionary: กตัญญู, which happens to have a similar synonym *and* an alternate spelling! ha!
The RID definition of กุฏิ contains "{cf. Tamil: กูฏุ = รังนก}".
Are there more such words? Are they rare simply because the consonants are, or are these combinations specifically avoided by using another consonant?



