Supposing
If
adverb
The kanji itself means temporary. When you add the に, we're asking you to imagine a situation temporarily, so the meaning changes to supposing or if.
かりに
The reading is kun'yomi, so here's a mnemonic to remember it:
If you don't mind, could you carry (かり) this for me? Supposing it's not too much trouble, of course.
仮にコウイチが『トーフグはめすだ』と言っても、多くのユーザーはそのいけんに反対するんじゃないだろうか。
Even if Koichi said, "Tofugu is female," I believe many users would have opposing opinions.
仮にトーフグにさいあくのじたいがおきたとしたら、ライフタイムメンバーの人たちはどうなるんですか？
Supposing the worst were to happen to Tofugu, what would happen to lifetime members?
え？あの娘の胸は風船で作られているって？仮にそうだとしても、だから何なんだよ！
What? Her boobs are made of balloons? Supposing that were true, who cares?