olemus
brauseriaken (enamasti reklaamiv), mis on peidetud
külastatava veebisaidi akna taha ja
ilmub nähtavale teda katva akna sulgemisel

Wiktionary:
(Internet) a pop-up advertisement that appears behind the window that triggers its appearance, and thus cannot initially be seen

piltlikult
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSB6lAWLhTOMsjfLWyPXo91jnjZ2Fulqb_OoZBAiF_pzjvhrwn0Kw

https://www.youtube.com/watch?v=1qhKIBb9MLE

ülevaateid
https://www.quora.com/What-types-of-websites-usually-use-pop-under-ads

https://cointraffic.io/blog/the-advantages-of-pop-under-ads-for-advertisers-and-publishers/

https://growtraffic.com/blog/2016/09/list-best-popunder-networks

https://deniswu.org/wp-content/uploads/2014/09/Zha-Wu-2014.pdf

https://www.businessofapps.com/ads/popunder/

tõrje
https://www.computerhope.com/issues/ch000491.htm

https://itstillworks.com/block-pop-unders-6834188.html

http://botcrawl.com/pop-under-advertisements-removal/

vt ka
- hüpik-