officious \uh-FISH-uhs\ (adjective) - Marked by excessive eagerness in offering services or advice where they are neither requested nor needed; meddlesome.
"You are too officious
In her behalf that scorns your services.
Let her alone: speak not of Helena,
Take not her part; for if thou dost intend
Never so little show of love to her,
Thou shalt aby it." -- William Shakespeare, 'A Midsummer Night's Dream'
Officious comes from Latin officiosus, obliging, dutiful, from officium, dutiful action, sense of duty, official employment, from opus, a work, labor + -ficere, combining form of facere, to do, to make. It is related to official, of or pertaining to an office or public trust.