›to improve something so that it works better or is more effective: It's quite simple to upgrade the indexing software.All the entrances to the building have been upgraded with ramps and handrails.
›ITto get new computers or other equipment that is better than you had before: So much of our business is now online we had to upgrade our entire system.The network is being upgraded.
›HRto give a person a more important job or to state that their job is more important than it was before: upgrade sb to sthCongratulations, I hear you've been upgraded to divisional manager. → Comparedowngradeverb
›FINANCEto state that something such as a company is likely to produce more profit or growth, to be better able to pay back debt, etc. than was previously thought: upgrade a forecast/outlook/expectationAnalysts had hoped to upgrade their earnings forecasts for the group.upgrade a rating/statusThe retailer's stock hit a 52-week high after Morgan Stanley upgraded its rating on the company. → Comparedowngradeverb
›TRANSPORTto get better travel arrangements than you originally paid for: upgrade sth (from sth) to sthOur plane tickets were upgraded to business class.We will upgrade your rental car from mid-size to full-size.