[ahy-suh-bath-uh-thurm] /ˌaɪ səˈbæθ əˌθɜrm/
a line on a chart or diagram of a body of water, connecting depths having the same temperature.
/ˌaɪsəʊbaɪˈlætərəl/ adjective 1. (botany) (esp of a leaf) capable of being divided into symmetrical halves along two different planes
[ahy-suh-bront] /ˈaɪ səˌbrɒnt/ noun, Meteorology. 1. a line on a weather map or chart connecting various points where a given phase of thunderstorm activity occurred simultaneously.
[ahy-suh-byoo-teyn, -byoo-teyn] /ˌaɪ səˈbyu teɪn, -byuˈteɪn/ noun, Chemistry. 1. a colorless, flammable gas, C 4 H 10 , used as a fuel, as a refrigerant, and in the manufacture of gasoline by alkylation.
[ahy-suh-byoot-l-een] /ˌaɪ səˈbyut lˌin/ noun, Chemistry. 1. a colorless, very volatile liquid or flammable gas, C 4 H 8 , used chiefly in the manufacture of butyl rubber.