In Chinese, there is a typical word formation method that uses the so-called "virtual character" （虚字）. The virtual characters can mean something or mean nothing but just a placeholder. If it means something, it may not mean exactly the same thing as the original definition.
左挑右选 - To hesitate to make the decision on which one to pick. In this compound word, "挑" and "选" are 实字（actual character）, but "左" and "右" are 虚字, which does not actually mean "left" and "right".
Similarly, in the word 前看后看, (or 瞻前顾后), "前" and "后" could be 虚字 that may or may not mean exactly "forwards" and "backwards".
When you translate the compound words formed by two, three, or four Chinese characters, you'd better take it as a whole instead of a combination result of character-by-character.
你学习的时候，不要三心二意，东张西望。= You should concentrate when you study. (not halfhearted) (but to translate 东张西望 into look around is not quite correct).
昨天下了大雨，那个老墙呼啦一下倒了。= It rained heavily yesterday and that old wall failed altogether. (呼啦 = whooshing). You can not ask what the "呼" means and the "啦" means.
In some dialects, you can hear the following words:
犄角旮旯，乱七八糟，糊里巴涂，脏拉吧唧, 小气吧啦, etc.
- 虚字 is not 虚词. 虚词 means function words for grammar.