is·allobar \(ˈ)īs also (ˈ)īz+\noun Etymology: International Scientific Vocabulary is- + all- + -bar (as in isobar) : an imaginary line or a line on a chart connecting the places of equal change of atmospheric pressure within a specified time • is·al·lo·bar·ic\(|)ī|salə|bärik, (|)ī|za-, -bar-\adjective