explanation

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act or process of explaining.
• noun Something that explains.
• noun A mutual clarification of misunderstandings; a reconciliation.

from The Century Dictionary.

• noun The act of explaining.
• noun The process of showing by reasoning or investigation the causal or logical antecedents or conditions of some thing or event which is to be accounted for; specifically, the making clear by reasoning how certain observed or admitted facts may have been brought about by the action of known principles, if a certain supposition is allowed; the unification of a confused mass of facts, by means of a single known or supposed fact from which they would all necessarily or probably result.
• noun That which is adduced as explaining or seeming to explain; specifically, a meaning or interpretation assigned; the sense given by an expounder or interpreter.
• noun An inquiry into language used, actions, or motives, with a view to adjust a misunderstanding and reconcile differences; hence, reconciliation or reëstablishment of good understanding between persons who have been at variance.
• noun Synonyms Explication, elucidation, description.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act of explaining, expounding, or interpreting; the act of clearing from obscurity and making intelligible.
• noun That which explains or makes clear.
• noun The meaning attributed to anything by one who explains it; definition; interpretation; sense.
• noun A mutual exposition of terms, meaning, or motives, with a view to adjust a misunderstanding, and reconcile differences; reconciliation; agreement.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The act or process of explaining
• noun Something that explains, makes understandable
• noun euphemistic An excuse, apologetic justification not based on enough evidence

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a statement that makes something comprehensible by describing the relevant structure or operation or circumstances etc.
• noun thought that makes something comprehensible
• noun the act of explaining; making something plain or intelligible