"Intelligence refers to intellectual functioning."
https://www.apa.org/topics/intelligence/
"Definition of intelligence
1a(1) : the ability to learn or understand or to deal with new or trying situations : reason also : the skilled use of reason
(2) : the ability to apply knowledge to manipulate one's environment or to think abstractly as measured by objective criteria (such as tests)"
https://www.merriam-webster.com/dictionary/intelligence
"capacity for learning, reasoning, understanding, and similar forms of mental activity; aptitude in grasping truths, relationships, facts, meanings, etc."
https://www.dictionary.com/browse/intelligence
"There is no agreed definition or model of intelligence. By the Collins English Dictionary, intelligence is ‘the ability to think, reason, and understand instead of doing things automatically or by instinct’."
https://www.psychologytoday.com/us/blog/hide-and-seek/201811/what-is-intelligence
"Defining and classifying intelligence is extremely complicated. Theories of intelligence range from having one general intelligence (g), to certain primary mental abilities, and to multiple category-specific intelligences."
https://www.simplypsychology.org/intelligence.html
"Human intelligence, mental quality that consists of the abilities to learn from experience, adapt to new situations, understand and handle abstract concepts, and use knowledge to manipulate one’s environment."
https://www.britannica.com/science/human-intelligence-psychology