AER or Aer may refer to: Biology Aerides, an orchid genus, abbreviated Aer Agranular endoplasmic reticulum, a cell organelle Apical ectodermal ridge, critical component of vertebrate limb development Albumin Excretion Rate Finance Annual equivalent rate, a notational interest rate Average earnings ratio, in stocks Administrative expense ratio, a ratio of general and administrative expenses to total revenue Languages Aer language, an Indo-Aryan language of Pakistan Eastern Arrernte language, an Arandic dialect cluster of Australia (ISO-639: aer) Music Aer (band), a hip-hop band Aer (album), an album by Swiss pianist and composer Nik Bärtsch's band Mobile Organizations A.E.R. (automobile), a French former car manufacturer AER (motorcycles), a British motorcycle manufacturer Action For Economic Reforms, a public-interest research organization in the Philippines Advanced Engine Research, an endurance racing car engine manufacturer AerCap, an aircraft lessor (NYSE stock symbol AER) Aer Lingus, airline from Ireland Agri-Energy Roundtable, a non-governmental organization accredited by the United Nations Algoma Eastern Railway, a former Canadian railway that operated in the province of Ontario Annual Equivalent Rate, as used in the UK Atmospheric and Environmental Research, an American scientific research agency owned by Verisk Analytics Army Emergency Relief Assembly of European Regions, an independent network of European Regions Australian Energy Regulator Places Aer (Sendai), a skyscraper in Japan Sochi International Airport, Russia (IATA airport code) Publications All England Law Reports, covering the court system in England and Wales American Economic Review Religion and mythology Aër, a liturgical item in the Greek Orthodox Church Air (classical element), in Greek mythology Other uses AER: Memories of Old, a 2017 adventure video game developed by Forgotten Key and published by Daedalic Entertainment All-electric range, the driving range of a vehicle using only electrical energy for propulsion