"most frequently searched" is correct and usable in written English.
For example, you could use it in a sentence like this: "Google searches are among the most frequently searched topics on the internet."
In countries like Italy and Russia, Quinn was one of the most frequently searched and quickest-growing terms, and ended up being the most highly-searched movie character all year (almost 7 million searches more than Batman).
hgtv.com, the most frequently searched term is "quilts" - but he is "amazed at the details people pick up on".
This gulf comes across powerfully in the entry on Mao, one of the most frequently searched and edited topics in Chinese, and in items on historical watersheds, like the Tiananmen Square massacre, the Great Leap Forward and the Cultural Revolution.
As such, chemicals/drugs are one of the topics most frequently searched in PubMed [2, 3].
Chemical and drug names are among the entity types most frequently searched in the PubMed database [1].
Perhaps tellingly, Facebook's own algorithm of 'common searches' is highlighting the term 'delete account' as the most frequently searched for in the help section.
Bradford Cross's Prismatic serves up a custom feed of the news and ideas that most reflects what I most frequently search for.
The most frequently searched-for Internet term in the Washington area this year is "fcps blackboard," according to Google.
Each of the top 10 most frequently searched-for genes has been queried more than 300 times (Table 2).
Intracranial hypertension was the most frequently suspected abnormality, and most often searched by young operators (p < 0.001).
In the clarification today, Google said: "we do not simply retrieve the most frequently-searched terms for the period — the truth is, they don't change that much from year to year…Instead, we looked for those searches that were very popular in 2006 but were not as popular in 2005 — the explosive queries, the topics that everyone obsessed over.
