1. en- a prefix forming verbs that have the generalsense “to cause (a person or thing) to be in” the place, condition, or state named by the stem; more specifically, “to confine in or place on” (entomb); “to cause to be in” (enrich; enslave; entrust); “to restrict,” typically with the additional sense “on all sides, completely” (encircle; enclose; entwine). This prefix is also attached to verbs in order to make them transitive, or to give them a transitive marker if they are already transitive (enkindle; enliven; enshield).
2. en- a prefix meaning “within, in,” occurring in loanwords from Greek: energy; enthusiasm.
Etymology: ((< L) < Gk; c. in -1, in -2)
Definition of 'en-'
Webster Dictionary
1. en- a prefix signifying in or into, used in many English words, chiefly those borrowed from the French. Some English words are written indifferently with en-or in-. For ease of pronunciation it is commonly changed to em-before p, b, and m, as in employ, embody, emmew. It is sometimes used to give a causal force, as in enable, enfeeble, to cause to be, or to make, able, or feeble; and sometimes merely gives an intensive force, as in enchasten. See In-
2. en- a prefix from Gr. / in, meaning in; as, encephalon, entomology. See In-
Definitions of en- 
