(5) Ambigram
Ambigram was added to the Oxford English Dictionary in March 2011, and the Merriam Webster dictionary included it in September 2020.
A symmetrical ambigram can be called "homogram" (contraction of "homo-ambigram") when it remains unchanged after reflection, and "heterogram" when it transforms. The above figure is an example of Homogram.
Now with the help of Computer and special Ambigram fonts, many Ambigrams can be created easily. One example from the net is copied below:
Prefix Ambi means Around, About, Both. There are a plethora of words having this root. A few words with the same root are listed below:
Amble: Walk leasurely about.
Ambidexter/ Ambidextrous: One who uses both hands with skills. Also Ambi-handed.
Ambiparous: having both leaves and flowers.
Ambivert : A person whose nature combines those of the introvert and extrovert.
Amburbial : relating to a circuit of a city. Encompassing or surrounding a city.
Perambulator: one who travels around, baby carriage.
Ambisinister: Clumsy with both hands.
Ambipedal: Able to use both feet with equal ease. Footballers Neymar and Christiano Ronaldo are ambipedal footballers. In the past Zidane and Socretes have been ambipedal.
There are many more words starting with the root Ambi. For example: Ambition,ambitious, ambiguity, ambiguous, ambit, ambient, ambilateral (bilateral), Ambivalence, Ambivalent, ambitendency, , ambulance, ambipedal, ambisexuality, ambilingual, ambilineally, ambidirectional etc.
There are still many words left! Find out:)