... sharply 73 drop-off n A decline in a business's sales, in the occurrence of an event, or in the interest some people have in something, is a drop-off There has been a drop-off in traffic deaths thanks ... prevented from moving, progressing, or flowing normally, it is backed up Let's take the train downtown Traffic is always backed up at this time of the morn in a Infinitive present tense -ing form past ... assembly line is going to back up if Erik doesn't get the parts he needs soon backup n A backup is a situation in which something is being prevented from moving, progressing, or flowing normally...