Sticktoitiveness

This word might seem a little (but probably only a little) clearer if we show its alternate spelling: stick-to-it-ive-ness. It is a lovely example of how English likes to put different words together with prefixes and suffixes to make new words. These compounds are generally hyphenated, but as they become more common, they often turn into one word, as in this case.

Sticktoitiveness is a noun used to described the quality of perseverance or tenacity. It comes from the phrasal verb to stick to something. When you do this, you don't change or give up.