(adapted from: http://www.thefreedictionary.com/environment)
It is the aggregate of social and cultural conditions that affect nature and the factors which affect the survival and form of organisms and objects. It is the position or characteristic position of a linguistic element in a sequence.
(adapted from http://www.merriam-webster.com/dictionary/Environment)
Environment is the external conditions, resources, stimuli etc. with which an organism interacts. It includes all of the biotic and abiotic factors that surround and affect the survival and development of an organism or population. The environments maybe regarded as natural environment or built environment. They may also be marine, atmospheric, or terrestrial according to their attributes.
BIOTIC: of, relating to, or resulting from living things, esp. in their ecological relations
ABIOTIC:physical rather than biological; not derived from living organisms.
(adapted from http://www.biology-online.org/dictionary/Environment)
In short, environment is our surroundings, affects us and others, and is affected by us.