The term "obsolescently" has its roots in the word "obsolescent," which refers to something that is becoming outdated or obsolete. There are several synonyms for "obsolescently" that can be used to convey a similar meaning. These include "outmodedly," "archaically," "passely," "antiquatedly," and "datedly." These words suggest that something is no longer in fashion or has fallen out of use. Whether referring to an outdated technology or a once-popular fashion trend, using these synonyms for "obsolescently" can help to communicate a sense of aging or decline.