I've seen many references to TCP/IP as meaning IP + everything-on-top, usually when talking about other networking technologies like UUnet, OSI, etc. Also as the TCP/IP stack, usually meaning the (Free)BSD networking code used in other systems.

It's not that TCP is a catch-all term, but "TCP/IP" is often used that way.

https://en.wikipedia.org/wiki/Internet_protocol_suite

The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP).

For that matter, the classic networking text by Douglas Comer is Internetworking with TCP/IP and it does cover UDP, ICMP, ARP, DHCP, DNS, etc.