the GNU version of the Collaborative International Dictionary of English
adj. Giving particular attention; habitually attentive to what passes; observant{1}
The Century Dictionary and Cyclopedia
Watchful; observant; attentive.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. quick to notice; showing quick and keen perception
Word Usage
"Snowflakes, fingerprints and yes, people are so unique and diverse that I find pleasure in observing others and witnessing the wonderful and dynamic individuals who will be [...]"