How to sign: remove by passing through a filter
"filter out the impurities";
Similiar / Same: filter, filtrate, separate out, filter out
Categories: separate
How to sign: to exert much effort or energy
"straining our ears to hear";
Similiar / Same: strive, reach
Categories: drive, labor, labour, push, tug
Within this category: extend oneself, kill oneself, trouble oneself