From Longman Dictionary of Contemporary Englishbuild up phrasal verb1 increase graduallyINCREASE IN ACTIVITY, FEELINGS ETC if something builds up somewhere, or if you build it up, it gradually becomes bigger or greater the rate at which the pension builds upbuild something ↔ up The museum has built up a fine art collection. → build-up2 develop build something ↔ up to make something develop or formbuild something ↔ up into He’s built up the family firm into a multinational company.3 feelingINCREASE IN ACTIVITY, FEELINGS ETC if a feeling builds up, or if you build it up, it increases gradually over a period of time If you don’t express your feelings, frustration and anger can build up.build up something You have to build up trust.4 make healthy build somebody/something ↔ upCURE to make someone well and strong again, especially after an illness Taking exercise will build up your strength.5 praise build somebody/something ↔ upPRAISE to praise someone or something so that other people think they are really good, or so that they have more confidence The coach has been building his men up before the match.6 HOPE build up somebody’s hopes (also build somebody's hopes up) to unfairly encourage someone to think that they will get what they hope for Don’t build your hopes up too much. → build→ See Verb table
Examples from the Corpus
build up• A huge backlog of work had built up during my absence.• Fertilizers can contain salts that build up in the soil.• I could feel the anger building up inside me.• As the temperature rises, the pressure builds up inside the chamber.• Traffic is building up on the southern exit of the motorway.• The pressure built up over the year, and eventually I had to leave my job.• Deposits of lime will stick to the surface and build up over the years.build into• It seems that people find it easier to find fault with ideas than to build them up into something better.• To switch channels, you might walk into another building on fly up into the clouds.build-upˈbuild-up noun [countable usually singular] 1 INCREASE IN ACTIVITY, FEELINGS ETCan increase over a period of timebuild-up of a heavy build-up of traffic on the motorway2 INTRODUCEa description of someone or something before an event, in which you say they are very special or important The presenter gave her a big build-up.3 PREPAREthe length of time spent preparing an event I was running 20 miles a week in my build-up for the race. → build up at build1Examples from the Corpus
build-up• Deal with any problems when necessary, so preventing a build-up of strain.• The changing world climate is probably due to a build-up of harmful gases such as carbon dioxide.• Scientists are warning of a dangerous build-up of chemicals in the water.• The players always feel a huge build-up of tension and nerves before an important game.• Experts believe the absence of water in the toilet allowed a lethal build-up of methane gas.• This could signal the biggest military build-up since the Cold War.• Watch out for greasy oil build-up.• It depends on a simple and regular mechanism, the build-up of errors with time.• The build-up of frustration he had felt since he lost the part would not allow him to be silent.• The build-up of recessive genes increases the incidence of genetically determined diseases, such as sickle-cell anaemia in humans. 