1. To extend the duration or time period of something; to make something last longer
The project manager decided to lengthen the span of the construction timeline by three months.
O gerente do projeto decidiu prolongar o período da linha do tempo da construção por três meses.
2. To increase the distance or extent of an arch, bridge, or structural element
The engineers had to lengthen the span of the bridge to cross the wider river.
Os engenheiros tiveram que estender o vão da ponte para atravessar o rio mais largo.