Fill in for (someone)
To replace someone temporarily.My friend is filling in for the librarian this week.
Fill a prescription
To get some medicine from a pharmacy (drug store) with the orders from a doctor.The man went to the drug store to fill a prescription.
Figure out (someone or something) figure (someone or something) out
To try to understand someone or something, to solve something.I finally figured out how to use the new DVD recorder.
Figure on (something)
To depend on something, to be sure about something.You can figure on many people coming to the party next week.
Fighting chance
A good possibility of success if you try hard.I did not have a fighting chance to get my job application finished on time.
Fight (someone or something) tooth and nail
To fight against someone or something with great energy.The citizens fought the government tooth and nail over the government plans to build the... Read more →
Fight like cats and dogs
To argue and fight with someone (usually used for people who know each other).The two children were fighting like cats and dogs when we entered... Read more →
Fight against time
To hurry to do something quickly, a fight to do something quickly.The rescue party was fighting against time to save the men who were trapped in... Read more →
Fight a rearguard action
To try very hard to prevent something from happening when it is probably too late to prevent it.The government is fighting a rearguard action to... Read more →
Fifty-fifty
Equally, evenly.We divided the cost of the trip fifty-fifty.