Sanskrit dictionary (beta)

A vocative particle used in addressing persons, and translateable by 'o', 'sir', 'oh', 'halloo', 'ah'; (it drops its final visarga before vowels and soft consonants); कः कोऽत्र भोः Ś.2; अयि भो महर्षिपुत्र Ś.7; it is sometimes repeated; भो भोः शंकरगृहाधि- वासिनो जानपदाः Māl.3; भो भोः पण्डिताः श्रूयताम् H. भोस् is said to have, in addition, the senses of 'sorrow' and 'interrogation'.

(from भवस् vocative case of भवत् quod vide; before vowels and soft consonants भो; before hard consonants भोस् and भोः; the latter form also in pause confer, compare Pa1n2. 8-3, 17 etc.; but there is occasional confusion of these forms, especially in later literature; often also भोभोः .), an interjection or vocative case particle commonly used in addressing another person or several persons Equivalent to O! Ho! Hallo l, in soliloquies Equivalent to alas! S3Br. etc. etc. (according to Lexicographers a particle of sorrow and of interrogation).

[bhos] interjection [contraction of bhavas, Veda, Vedic vocative of bhavat] used in addressing persons male and female (often several), Sir! oh! ho there! hark! often repeated bho bhoh: in soliloquies= alas! (the final visarga is retained before hard letters only, being dropped before vowels and soft consonants.)