The Electronic Engineering Dictionary is a blog that collates a glossary on terms belonging to the field of electronic engineering. Just like other glossaries, it is arranged in alphabetical order.
You can find it at this link: http://www.interfacebus.com/Glossary-of-Terms.html
www.engineering-dictionary.com follows a similar structure, however, its content covers the field of engineering in general and you can search for the terms you need both in alphabetical order and in the search bar.
You can find its contents at the following link: www.engineering-dictionary.com
Finally, we have the Electropedia, collated by the International Electrotechnical Commission (IEC). It is the world leading organization that prepares and publishes intellectual standards for all electronic and engineering-related technologies. It contains all the terms and definitions of the international electronic vocabulary. It is an online terminology database with more than 22,000 entries in English and French organized by theme.
You can find it at this link: https://www.electropedia.org/iev/iev.nsf/Welcome?OpenForm