in ‧ ter ‧ ject /ˌɪntəˈdʒekt $ -ər-/ BrE AmE verb [intransitive and transitive] formal
[ Date: 1500-1600 ; Language: Latin ; Origin: past participle of intericere , from jacere 'to throw' ]
to interrupt what someone else is saying with a sudden remark:
‘That’s absolute rubbish!’ he interjected.