Definition of (おと)

noun
1.
younger brother (of an older brother), younger sister (of an older sister)(archaism)
2.
youngest child(archaism)
prefix
3.
young, younger, youngest(archaism)
4.
young and beautiful, cute(archaism)
Other readings:
【おと】
Related Kanji
younger brother, faithful service to elders
the latter, duplicate, strange, witty, fishhook radical (no. 5)