The explanation of Wako Wako is as follows:
To be hidden from view.
It seems to disappear and appear.
Describes what seems to be there or not there, untrue and unclear.
若隐若现 [ruò yǐn ruò xiàn]
Origin: Tang Taizong, "Preface to the Sacred Teachings of the Three Tibetans of the Great Tang Dynasty": "No extinction, no birth; after a thousand kalpas, it is not ancient; if it is hidden, if it is present; if it is blessed, it is ever present."
Idiomatic Usage: conjunctive; as predicate, determiner, dative; describing vague memory.
Example sentences:
1. The sky was overcast, and the sun was hidden behind the clouds.
2. A misty fog shrouded the house and trees in the distance, which were hidden from view.
Near synonyms:
I. Hidden [yǐn yǐn yuē yuē]
Interpretation: means to look or sound vague, not very clear, and not very obvious in feeling.
Origin: Qing Dynasty - Li Ruzhen (李汝珍)《镜花缘》第十回: "Only to see the mountain slope beside the vague, but like flinging out an arrow, straight to the face of the big insect shot."
Example sentence: I ~ remember a big tree with a swing chained to it in front of my old house.
II.若有若无 [ruò yǒu ruò wú]
Index: as if there were and as if there were not, vague and indistinct.
Citation: She knew very well that he had long been ~ to her and did not care about her. Shating's "Amoy Gold" VIII
Source: Ming Hong Yingming's "Vegetable Roots Tan - Leisure": "If there is something, half real, half illusory, it is most enough to please people's minds and open up people's nature and spirit. It is a wonderful place between heaven and earth."
Example sentence: The wind, gently blowing up the white long skirt, hovered around the feet, scraping up the cherry blossoms on both sides of the river, fluttering in the sky. Early in the morning above the river surrounded by indistinct smoke, depicting the woman's appearance ~, as if she were an unearthly fairy descending from the earth to swim on the fairy-like bridge.