illegitimately

adverb

1. in a manner disapproved or not allowed by custom

   adv.all

   Examples

   He acted illegitimately when he increased the rent fourfold.

   Synonyms illicitly

   Antonyms lawfully legitimately licitly

   Source: WordNet 3.0

2. of biological parents not married to each other

   adv.all

   Examples

   This child was born illegitimately.

   Synonyms out of wedlock

   Antonyms legitimately

   Source: WordNet 3.0

3. In a illegitimate manner; unlawfully.

   adverb

   Source: webster1913