deleterious

We heard this word on "Homeland" last night (new latest obsession/TV addiction that is keeping me up WAY past my bedtime!). It's so good!

This is my new favorite word!

deleterious
del·e·te·ri·ous Adjective /ˌdeliˈti(ə)rēəs/ 

Synonyms:
adjective: harmful, injurious, noisome, detrimental, prejudicial, noxious, maleficent, bad,mischievous, pernicious, malign, nocuous, hurtful, baneful, baleful, destructive, inimical

1. Causing harm or damage