given (CERTAIN)

given (CERTAIN) Show phonetics
noun [C]
something which is certain to happen:
You can take it as a given that there will be champagne at the wedding.

(from Cambridge Advanced Learner's Dictionary)

When Your Product Becomes a Commodity

http://hbswk.hbs.edu/item/5830.html
Like death and taxes, commoditization of your products is a given. Marketing professor John Quelch offers tips for delaying the inevitable and dealing with it once it arrives.

given
━━ v., a., n. giveの過去分詞; …と仮定すると; 【法】（署名）作成された; 与えられた; 一定［特定］の; ふけっている, 癖がある ((to)); 既知の事項［状況］.
given name　〔米〕 （姓に対する）名 （first name）.