One single kanji may have more than one different readings. Those readings are classified in three different groups: On'yomi, Kun'yomi and Nanori.
Meaning of the kanji. This meaning may come from both the On'yomi and the Kun'yomi readings.
Each stroke in a kanji ideogram is written following a specific order. This order is supposed to be always the same and follows specific rules.
The basic rule is to write from top to bottom and from left to right.
Most kanji can be decomposed into smaller parts. Those parts are called radicals and they are often semantic indicators of the meaning of the character.
Some of most popular compounds containing this kanji. The meaning of those words might or might not be related with the meaning of the kanji itself.
katakana, angular Japanese syllabary used primarily for loanwords
hiragana, cursive Japanese syllabary used primarily for native Japanese words (esp. function words, inflections, etc.)
assumption, supposition, hypothesis
supposing, even if, granting that, for argument's sake
Some other useful information about this kanji. Like the number of strokes or the relative frequency of occurrence of a character in modern Japanese.