be / keep on (and on) about sb/sth

/biː kˈiːp ˌɒn and ˌɒn ɐbˌaʊt ˌɛsbˈiː slˈaʃ ˌɛstˌiːˈeɪtʃ/

/biː kˈiːp ˌɑːn ænd ˌɑːn ɐbˌaʊt ˌɛsbˈiː slˈæʃ ˌɛstˌiːˈeɪtʃ/

to be / keep on (and on) about sb/sth

to continue talking about a certain subject in a tediously and lengthy manner

Examples

1. They're on about fifteen percent of menus in the U.S., but the number of menu Spam is on has increased in recent years.

2. Our guests were on and on about the food.

3. So, as I said, we're on about hour two of this missile flying.

4. So, as I said, we're on about hour two of this missile flying.