I've been doing a lot of long words lately, so how about a short one to start off the week?
erg (ERG) - n., a large desert region of sand dunes with little or no vegetation.
Especially in the Sahara, but not limited to there. The kind of landscape you think of when you hear desert, with a shifting sea of dunes. Technically this is erg2, where erg1 is the unit of energy. Given the Saharan specificity, it may not be surprising that it comes (via French) from Maghrebi Arabic ʾerg, corresponding to Standard Arabic ʾirq, vein, referring to the veinlike appearance of the dunes).

Thanks, WikiMedia!
---L.
erg (ERG) - n., a large desert region of sand dunes with little or no vegetation.
Especially in the Sahara, but not limited to there. The kind of landscape you think of when you hear desert, with a shifting sea of dunes. Technically this is erg2, where erg1 is the unit of energy. Given the Saharan specificity, it may not be surprising that it comes (via French) from Maghrebi Arabic ʾerg, corresponding to Standard Arabic ʾirq, vein, referring to the veinlike appearance of the dunes).

Thanks, WikiMedia!
---L.