pathological
adjective
path·o·log·i·cal ˌpa-thə-ˈlä-ji-kəl 
variants or less commonly pathologic
ˌpa-thə-ˈlä-jik
1
: of or relating to pathology
pathological research
A pathological examination led to the diagnosis.
2
: altered or caused by disease
pathological changes in the body
also : indicative of disease
pathological symptoms
3
: being such to a degree that is extreme, excessive, or markedly abnormal
a pathological liar
pathological fear
pathologically
ˌpa-thə-ˈlä-ji-k(ə-)lē
adverb 
Example Sentences
He is a pathological liar. She has a pathological fear of heights. pathological changes in the body
Recent Examples on the Web Here, more explicitly than in her portrait of Ray, Aviv joins an existing discourse about psychopharmacology, raising by now familiar concerns about the overmedication of Americans, and the impulse to treat regular human unhappiness as pathological. 
Jordan Kisner, The Atlantic, 13 Sep. 2022 Paleopathology, or the study of pathological conditions found in ancient human and animal remains, is growing as scientists across different disciplines work together to understand the lives of dinosaurs. Ashley Strickland, CNN, 10 Feb. 2022 Nothing pathological in them, with rare exceptions. BostonGlobe.com, 29 Apr. 2022 In recent years, there has been a move to embrace neurodiversity in the workplace, or valuing that there are normal, non-pathological variations in mental functioning. Forbes, 26 Oct. 2021 Each one is like a beloved child: unique and the product of a sometimes pathological level of love and care. Kelly Allen, House Beautiful, 8 July 2022 As the garrulous toddler turns into a petulant adolescent, Brian’s protectiveness toward Charles, who longs for adventure — Hawaii, glimpsed on the TV, really grabs him — is reasonable, not pathological. Sheri Linden, The Hollywood Reporter, 16 June 2022 In comparison, Alice’s fascination with the Artist seems pathological. Hua Hsu, The New Yorker, 29 Apr. 2022 When justice is sought in the wake of a scam, skepticism is positioned as the norm, while gullibility is treated as a maladaptive, pathological, deviant form of socioeconomic being. Hannah Zeavin, Harper’s Magazine , 22 June 2022 See More
Jordan Kisner, The Atlantic, 13 Sep. 2022 Paleopathology, or the study of pathological conditions found in ancient human and animal remains, is growing as scientists across different disciplines work together to understand the lives of dinosaurs. Ashley Strickland, CNN, 10 Feb. 2022 Nothing pathological in them, with rare exceptions. BostonGlobe.com, 29 Apr. 2022 In recent years, there has been a move to embrace neurodiversity in the workplace, or valuing that there are normal, non-pathological variations in mental functioning. Forbes, 26 Oct. 2021 Each one is like a beloved child: unique and the product of a sometimes pathological level of love and care. Kelly Allen, House Beautiful, 8 July 2022 As the garrulous toddler turns into a petulant adolescent, Brian’s protectiveness toward Charles, who longs for adventure — Hawaii, glimpsed on the TV, really grabs him — is reasonable, not pathological. Sheri Linden, The Hollywood Reporter, 16 June 2022 In comparison, Alice’s fascination with the Artist seems pathological. Hua Hsu, The New Yorker, 29 Apr. 2022 When justice is sought in the wake of a scam, skepticism is positioned as the norm, while gullibility is treated as a maladaptive, pathological, deviant form of socioeconomic being. Hannah Zeavin, Harper’s Magazine , 22 June 2022 See More Word History
Etymology
New Latin pathologicus "of the study of the passions, of the study of diseases" (borrowed from Greek pathologikós, from patho- patho- + -logikos, from -logia -logy + -ikos -ic entry 1) + -al entry 1
First Known Use
1656, in the meaning defined at sense 1
Medical Definition
pathological
adjective
patho·log·i·cal ˌpath-ə-ˈläj-i-kəl
variants also pathologic
-ik
1
: of or relating to pathology
a pathological laboratory
2
: altered or caused by disease
pathological tissue
also : indicative of disease
pathological lesions