熟語【じゅくご】 are basically kanji compounds that use two kanji's 音読み and creates a word out of it.
One common example of 熟語 is the word 今度【こんど】. This consists of the 音読み of the kanji 今 (English meaning: now) and the kanji 度 (English meaning: occurence/time). Put these two kanji together, and you get "this time/next time".
熟語 only use the 音読み of a kanji and never a 訓読み of it.
Here are some more prime examples of 熟語:
>>>勉＝ベン (exerting [efforts])
And some rather difficult 熟語:
>>>再＝サイ (again/second time)
I could go on forever with this ordeal, but hopefully, this is enough for you to understand the concept of 熟語.
ROMAJI version to come if enough people request it.
I should probably update my profile on this site more often...someday